This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is an investigator-initiated, multicenter, randomized, double-blind trial to test the effects of treatment of insulin resistance on the incidence of type 2 diabetes and on pancreatic B-cell function in adults with impaired glucose tolerance and clinical characteristics indicating insulin resistance.